title: Highly efficient α-C-sialylation promoted by (p-Tol)2SO/Tf2O with N-acetyl-5-N,4-O-oxazolidione protected thiosialoside as donor.
abstract: Based on a preactivation protocol with (p-Tol)2SO/Tf2O, a practical, straightforward, and high-yielding synthesis of α-sialyl C-glycosides was accomplished by coupling N-acetyl-5-N,4-O-oxazolidione protected thiosialoside with various trimethylsilyl enol ethers and allyltrimethylsilanes. High yields and excellent α-selectivities were obtained for the strong π-nucleophiles with large nucleophilicity values (N = 4.4-9.0), irrespective of whether silyl enol ethers, silyl ketene acetals or allyltrimethylsilanes were used for the electrophilic C-sialylation.
authors.affiliation: Department of Chemistry, Beijing Normal University, Beijing 100875, China.
authors.forename: Zhen-yuan
authors.initials: ZY
authors.lastname: Gu
authors.forename: Xiao-tai
authors.initials: XT
authors.lastname: Zhang
authors.forename: Jia-xin
authors.initials: JX
authors.lastname: Zhang
authors.forename: Guo-wen
authors.initials: GW
authors.lastname: Xing
mesh_terms: D000812:Anhydrides / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry*; D015394:Molecular Structure; D023303:Oxazolidinones / Q000737:chemistry*; D012794:Sialic Acids / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D000812:Anhydrides; D006027:Glycosides; D008698:Mesylates; D023303:Oxazolidinones; D012794:Sialic Acids; D013438:Sulfhydryl Compounds; D013454:Sulfoxides; C012077:trifluoromethanesulfonic acid